/*
 *
 * (C) COPYRIGHT ARM Limited. All rights reserved.
 *
 * This program is free software and is provided to you under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation, and any use by you of this program is subject to the terms
 * of such GNU licence.
 *
 * A copy of the licence is included with the program, and can also be obtained
 * from Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 *
 */





/**
 * @file mali_kbase_js_affinity.c
 * Base kernel affinity manager APIs
 */

#include <mali_kbase.h>
#include "mali_kbase_js_affinity.h"


STATIC INLINE mali_bool affinity_job_uses_high_cores(kbase_device *kbdev, kbase_jd_atom *katom)
{
	if (kbase_hw_has_issue(kbdev, BASE_HW_ISSUE_8987)) {
		kbase_context *kctx;
		kbase_context_flags ctx_flags;

		kctx = katom->kctx;
		ctx_flags = kctx->jctx.sched_info.ctx.flags;

		/* In this HW Workaround, compute-only jobs/contexts use the high cores
		 * during a core-split, all other contexts use the low cores. */
		return (mali_bool) ((katom->core_req & BASE_JD_REQ_ONLY_COMPUTE) != 0 || (ctx_flags & KBASE_CTX_FLAG_HINT_ONLY_COMPUTE) != 0);
	}
	return MALI_FALSE;
}

/**
 * @brief Decide whether a split in core affinity is required across job slots
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_device_data::runpool_irq::lock
 *
 * @param kbdev The kbase device structure of the device
 * @return MALI_FALSE if a core split is not required
 * @return != MALI_FALSE if a core split is required.
 */
STATIC INLINE mali_bool kbase_affinity_requires_split(kbase_device *kbdev)
{
	KBASE_DEBUG_ASSERT(kbdev != NULL);
	lockdep_assert_held(&kbdev->js_data.runpool_irq.lock);

	if (kbase_hw_has_issue(kbdev, BASE_HW_ISSUE_8987)) {
		s8 nr_compute_ctxs = kbasep_js_ctx_attr_count_on_runpool(kbdev, KBASEP_JS_CTX_ATTR_COMPUTE);
		s8 nr_noncompute_ctxs = kbasep_js_ctx_attr_count_on_runpool(kbdev, KBASEP_JS_CTX_ATTR_NON_COMPUTE);

		/* In this case, a mix of Compute+Non-Compute determines whether a
		 * core-split is required, to ensure jobs with different numbers of RMUs
		 * don't use the same cores.
		 *
		 * When it's entirely compute, or entirely non-compute, then no split is
		 * required.
		 *
		 * A context can be both Compute and Non-compute, in which case this will
		 * correctly decide that a core-split is required. */

		return (mali_bool) (nr_compute_ctxs > 0 && nr_noncompute_ctxs > 0);
	}
	return MALI_FALSE;
}

mali_bool kbase_js_can_run_job_on_slot_no_lock(kbase_device *kbdev, int js)
{
	/*
	 * Here are the reasons for using job slot 2:
	 * - BASE_HW_ISSUE_8987 (which is entirely used for that purpose)
	 * - In absence of the above, then:
	 *  - Atoms with BASE_JD_REQ_COHERENT_GROUP
	 *  - But, only when there aren't contexts with
	 *  KBASEP_JS_CTX_ATTR_COMPUTE_ALL_CORES, because the atoms that run on
	 *  all cores on slot 1 could be blocked by those using a coherent group
	 *  on slot 2
	 *  - And, only when you actually have 2 or more coregroups - if you only
	 *  have 1 coregroup, then having jobs for slot 2 implies they'd also be
	 *  for slot 1, meaning you'll get interference from them. Jobs able to
	 *  run on slot 2 could also block jobs that can only run on slot 1
	 *  (tiler jobs)
	 */
	if (kbase_hw_has_issue(kbdev, BASE_HW_ISSUE_8987))
		return MALI_TRUE;

	if (js != 2)
		return MALI_TRUE;

	/* Only deal with js==2 now: */
	if (kbdev->gpu_props.num_core_groups > 1) {
		/* Only use slot 2 in the 2+ coregroup case */
		if (kbasep_js_ctx_attr_is_attr_on_runpool(kbdev, KBASEP_JS_CTX_ATTR_COMPUTE_ALL_CORES) == MALI_FALSE) {
			/* ...But only when we *don't* have atoms that run on all cores */

			/* No specific check for BASE_JD_REQ_COHERENT_GROUP atoms - the policy will sort that out */
			return MALI_TRUE;
		}
	}

	/* Above checks failed mean we shouldn't use slot 2 */
	return MALI_FALSE;
}

/*
 * As long as it has been decided to have a deeper modification of
 * what job scheduler, power manager and affinity manager will
 * implement, this function is just an intermediate step that
 * assumes:
 * - all working cores will be powered on when this is called.
 * - largest current configuration is 2 core groups.
 * - It has been decided not to have hardcoded values so the low
 *   and high cores in a core split will be evently distributed.
 * - Odd combinations of core requirements have been filtered out
 *   and do not get to this function (e.g. CS+T+NSS is not
 *   supported here).
 * - This function is frequently called and can be optimized,
 *   (see notes in loops), but as the functionallity will likely
 *   be modified, optimization has not been addressed.
*/
mali_bool kbase_js_choose_affinity(u64 * const affinity, kbase_device *kbdev, kbase_jd_atom *katom, int js)
{
	base_jd_core_req core_req = katom->core_req;
	unsigned int num_core_groups = kbdev->gpu_props.num_core_groups;
	u64 core_availability_mask;
	unsigned long flags;

	spin_lock_irqsave(&kbdev->pm.power_change_lock, flags);

	core_availability_mask = kbase_pm_ca_get_core_mask(kbdev);

	/*
	 * If no cores are currently available (core availability policy is
	 * transitioning) then fail.
	 */
	if (0 == core_availability_mask)
	{
		spin_unlock_irqrestore(&kbdev->pm.power_change_lock, flags);
		*affinity = 0;
		return MALI_FALSE;
	}

	KBASE_DEBUG_ASSERT(js >= 0);

	if ((core_req & (BASE_JD_REQ_FS | BASE_JD_REQ_CS | BASE_JD_REQ_T)) == BASE_JD_REQ_T)
	{
		spin_unlock_irqrestore(&kbdev->pm.power_change_lock, flags);
		/* Tiler only job, bit 0 needed to enable tiler but no shader cores required */
		*affinity = 1;
		return MALI_TRUE;
	}

	if (1 == kbdev->gpu_props.num_cores) {
		/* trivial case only one core, nothing to do */
		*affinity = core_availability_mask;
	} else if (kbase_affinity_requires_split(kbdev) == MALI_FALSE) {
		if ((core_req & (BASE_JD_REQ_COHERENT_GROUP | BASE_JD_REQ_SPECIFIC_COHERENT_GROUP))) {
			if (js == 0 || num_core_groups == 1) {
				/* js[0] and single-core-group systems just get the first core group */
				*affinity = kbdev->gpu_props.props.coherency_info.group[0].core_mask & core_availability_mask;
			} else {
				/* js[1], js[2] use core groups 0, 1 for dual-core-group systems */
				u32 core_group_idx = ((u32) js) - 1;
				KBASE_DEBUG_ASSERT(core_group_idx < num_core_groups);
				*affinity = kbdev->gpu_props.props.coherency_info.group[core_group_idx].core_mask & core_availability_mask;

				/* If the job is specifically targeting core group 1 and the core
				 * availability policy is keeping that core group off, then fail */
				if (*affinity == 0 && core_group_idx == 1 && kbdev->pm.cg1_disabled == MALI_TRUE)
					katom->event_code = BASE_JD_EVENT_PM_EVENT;
			}
		} else {
			/* All cores are available when no core split is required */
			*affinity = core_availability_mask;
		}
	} else {
		/* Core split required - divide cores in two non-overlapping groups */
		u64 low_bitmap, high_bitmap;
		int n_high_cores = kbdev->gpu_props.num_cores >> 1;
		KBASE_DEBUG_ASSERT(1 == num_core_groups);
		KBASE_DEBUG_ASSERT(0 != n_high_cores);

		/* compute the reserved high cores bitmap */
		high_bitmap = ~0;
		/* note: this can take a while, optimization desirable */
		while (n_high_cores != hweight32(high_bitmap & kbdev->shader_present_bitmap))
			high_bitmap = high_bitmap << 1;

		high_bitmap &= core_availability_mask;
		low_bitmap = core_availability_mask ^ high_bitmap;

		if (affinity_job_uses_high_cores(kbdev, katom))
			*affinity = high_bitmap;
		else
			*affinity = low_bitmap;
	}

	spin_unlock_irqrestore(&kbdev->pm.power_change_lock, flags);

	/*
	 * If no cores are currently available in the desired core group(s)
	 * (core availability policy is transitioning) then fail.
	 */
	if (*affinity == 0)
		return MALI_FALSE;

	/* Enable core 0 if tiler required */
	if (core_req & BASE_JD_REQ_T)
		*affinity = *affinity | 1;

	return MALI_TRUE;
}

STATIC INLINE mali_bool kbase_js_affinity_is_violating(kbase_device *kbdev, u64 *affinities)
{
	/* This implementation checks whether the two slots involved in Generic thread creation
	 * have intersecting affinity. This is due to micro-architectural issues where a job in
	 * slot A targetting cores used by slot B could prevent the job in slot B from making
	 * progress until the job in slot A has completed.
	 *
	 * @note It just so happens that this restriction also allows
	 * BASE_HW_ISSUE_8987 to be worked around by placing on job slot 2 the
	 * atoms from ctxs with KBASE_CTX_FLAG_HINT_ONLY_COMPUTE flag set
	 */
	u64 affinity_set_left;
	u64 affinity_set_right;
	u64 intersection;
	KBASE_DEBUG_ASSERT(affinities != NULL);

	affinity_set_left = affinities[1];

	if (kbase_hw_has_issue(kbdev, BASE_HW_ISSUE_8987)) {
		/* The left set also includes those on the Fragment slot when
		 * we are using the HW workaround for BASE_HW_ISSUE_8987 */
		affinity_set_left |= affinities[0];
	}

	affinity_set_right = affinities[2];

	/* A violation occurs when any bit in the left_set is also in the right_set */
	intersection = affinity_set_left & affinity_set_right;

	return (mali_bool) (intersection != (u64) 0u);
}

mali_bool kbase_js_affinity_would_violate(kbase_device *kbdev, int js, u64 affinity)
{
	kbasep_js_device_data *js_devdata;
	u64 new_affinities[BASE_JM_MAX_NR_SLOTS];

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(js < BASE_JM_MAX_NR_SLOTS);
	js_devdata = &kbdev->js_data;

	memcpy(new_affinities, js_devdata->runpool_irq.slot_affinities, sizeof(js_devdata->runpool_irq.slot_affinities));

	new_affinities[js] |= affinity;

	return kbase_js_affinity_is_violating(kbdev, new_affinities);
}

void kbase_js_affinity_retain_slot_cores(kbase_device *kbdev, int js, u64 affinity)
{
	kbasep_js_device_data *js_devdata;
	u64 cores;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(js < BASE_JM_MAX_NR_SLOTS);
	js_devdata = &kbdev->js_data;

	KBASE_DEBUG_ASSERT(kbase_js_affinity_would_violate(kbdev, js, affinity) == MALI_FALSE);

	cores = affinity;
	while (cores) {
		int bitnum = fls64(cores) - 1;
		u64 bit = 1ULL << bitnum;
		s8 cnt;

		KBASE_DEBUG_ASSERT(js_devdata->runpool_irq.slot_affinity_refcount[js][bitnum] < BASE_JM_SUBMIT_SLOTS);

		cnt = ++(js_devdata->runpool_irq.slot_affinity_refcount[js][bitnum]);

		if (cnt == 1)
			js_devdata->runpool_irq.slot_affinities[js] |= bit;

		cores &= ~bit;
	}

}

void kbase_js_affinity_release_slot_cores(kbase_device *kbdev, int js, u64 affinity)
{
	kbasep_js_device_data *js_devdata;
	u64 cores;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(js < BASE_JM_MAX_NR_SLOTS);
	js_devdata = &kbdev->js_data;

	cores = affinity;
	while (cores) {
		int bitnum = fls64(cores) - 1;
		u64 bit = 1ULL << bitnum;
		s8 cnt;

		KBASE_DEBUG_ASSERT(js_devdata->runpool_irq.slot_affinity_refcount[js][bitnum] > 0);

		cnt = --(js_devdata->runpool_irq.slot_affinity_refcount[js][bitnum]);

		if (0 == cnt)
			js_devdata->runpool_irq.slot_affinities[js] &= ~bit;

		cores &= ~bit;
	}

}

void kbase_js_affinity_slot_blocked_an_atom(kbase_device *kbdev, int js)
{
	kbasep_js_device_data *js_devdata;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(js < BASE_JM_MAX_NR_SLOTS);
	js_devdata = &kbdev->js_data;

	js_devdata->runpool_irq.slots_blocked_on_affinity |= 1u << js;
}

void kbase_js_affinity_submit_to_blocked_slots(kbase_device *kbdev)
{
	kbasep_js_device_data *js_devdata;
	u16 slots;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	js_devdata = &kbdev->js_data;

	KBASE_DEBUG_ASSERT(js_devdata->nr_user_contexts_running != 0);

	/* Must take a copy because submitting jobs will update this member. */
	slots = js_devdata->runpool_irq.slots_blocked_on_affinity;

	while (slots) {
		int bitnum = fls(slots) - 1;
		u16 bit = 1u << bitnum;
		slots &= ~bit;

		KBASE_TRACE_ADD_SLOT(kbdev, JS_AFFINITY_SUBMIT_TO_BLOCKED, NULL, NULL, 0u, bitnum);

		/* must update this before we submit, incase it's set again */
		js_devdata->runpool_irq.slots_blocked_on_affinity &= ~bit;

		kbasep_js_try_run_next_job_on_slot_nolock(kbdev, bitnum);

		/* Don't re-read slots_blocked_on_affinity after this - it could loop for a long time */
	}
}

#if KBASE_TRACE_ENABLE != 0
void kbase_js_debug_log_current_affinities(kbase_device *kbdev)
{
	kbasep_js_device_data *js_devdata;
	int slot_nr;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	js_devdata = &kbdev->js_data;

	for (slot_nr = 0; slot_nr < 3; ++slot_nr)
		KBASE_TRACE_ADD_SLOT_INFO(kbdev, JS_AFFINITY_CURRENT, NULL, NULL, 0u, slot_nr, (u32) js_devdata->runpool_irq.slot_affinities[slot_nr]);
}
#endif				/* KBASE_TRACE_ENABLE != 0 */